From patchwork Wed Aug 27 15:19:26 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rob Clark X-Patchwork-Id: 4788971 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id D7BE89F2A9 for ; Wed, 27 Aug 2014 15:19:38 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C9AD32015E for ; Wed, 27 Aug 2014 15:19:37 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id A426720127 for ; Wed, 27 Aug 2014 15:19:36 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 362C66E05D; Wed, 27 Aug 2014 08:19:35 -0700 (PDT) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mail-qg0-f46.google.com (mail-qg0-f46.google.com [209.85.192.46]) by gabe.freedesktop.org (Postfix) with ESMTP id CFCBF6E05D for ; Wed, 27 Aug 2014 08:19:33 -0700 (PDT) Received: by mail-qg0-f46.google.com with SMTP id z60so383158qgd.19 for ; Wed, 27 Aug 2014 08:19:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id; bh=xyMkilRhxAqzTRNocGbThnwPceR5O+WBvF+cfi1s9PQ=; b=M6n7TqZhP4BZ0jHZZZZsRFND8BUs1ASg7LFc6ABPK9QIUG8T0DHtlFdTIp3lI8VVu0 gp0GgGY30NPUU0f5gdIEug8F0TedcmBNjFV8var3mirR1MknlpeoF1GEfUUzxWFVtpqd so/1qmOCNH3Wh1WG0yH9mOY4p+D0HGoV+01ILjRHAZyxPHAnz1Ve4gDODJa4dRSpbaxw hGXIhC36jpxcUF25Iz0tg5rz/kmzIlzoY1GdPoHSpJyWcknX4KHaKrhPkTx2O9qoVJwY MQa9fua9mvSSRMM3h0OcWNJT8SpG1+NwsMvm3CVk0qlDGrzdnq2Jiwfkw8lbEmUs9VJO Ha+Q== X-Received: by 10.229.236.8 with SMTP id ki8mr57573622qcb.12.1409152773295; Wed, 27 Aug 2014 08:19:33 -0700 (PDT) Received: from localhost ([2601:6:2c00:943:2677:3ff:fed3:ff40]) by mx.google.com with ESMTPSA id d62sm1011939qga.38.2014.08.27.08.19.32 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 27 Aug 2014 08:19:32 -0700 (PDT) From: Rob Clark To: linux-kernel@vger.kernel.org Subject: [PATCH] ww-mutex: clarify help text for DEBUG_WW_MUTEX_SLOWPATH Date: Wed, 27 Aug 2014 11:19:26 -0400 Message-Id: <1409152766-31320-1-git-send-email-robdclark@gmail.com> X-Mailer: git-send-email 1.9.3 Cc: dri-devel@lists.freedesktop.org X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Spam-Status: No, score=-4.1 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We really don't want distro's enabling this in their kernels. Try and make that more clear. Signed-off-by: Rob Clark Acked-by: Maarten Lankhorst --- lib/Kconfig.debug | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 07c2832..1b233fc 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -892,6 +892,10 @@ config DEBUG_WW_MUTEX_SLOWPATH the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this will test all possible w/w mutex interface abuse with the exception of simply not acquiring all the required locks. + Note that this feature can introduce significant overhead, so + it really should not be enabled in a production or distro kernel, + even a debug kernel. If you are a driver writer, enable it. If + you are a distro, do not. config DEBUG_LOCK_ALLOC bool "Lock debugging: detect incorrect freeing of live locks"